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What are Polymers? The shape and Polymer with no cross-links
Modifying polymers
·A polymer is a long-chained molecule that is size of the long-
Different polymers have different properties,
composed of individual units of ethene, called chain molecules
depending on the small molecules they were
monomers. in a fibre make
made from; but the properties of a polymer
the material what
can also be changed.
·Materials can be obtained or made from living it is and gives it it'
things and chemicals. These are known as natural s special
and synthetic materials. properties.
Polymer chains
·Many polymers, such as polythene,
contain long molecules that lie side by side.
These can uncoil and slide past each other,
making the material flexible.
Polymers Molecular Structure
·Long polymer chains have stronger forces
Ethene makes polythene of attraction than shorter ones. By making
the chains of a polymer longer, a stronger
By polymerising other small molecules, a wide and less flexible material is produced.
variety of different polymers can be made. C2
These synthetic materials have many uses.
A Life Cycle Assessment, or LCA, is a study
of the stages in the life of a manufactured
Getting the right material
product. It can be used to assess the
·The products that we use are made of different Material Properties Life Cycle Assessment
environmental impact of the manufacture
materials. Choosing the right material for each job
and use of different materials and
depends on the properties of that material.
·Manufacturers and designers have to choose the
The raw materials for making the
right materials to make their products. They
decide which materials to use based on their
properties and cost.
The energy used to manufacture it
The energy needed to use it
Solid materials can differ in the following ways:
· Melting point USE
The energy needed to maintain it
The chemicals needed to maintain it
· Strength in tension (when pulled)
· Strength in compression (when pushed) Nylon is used
The raw materials for making the
· Stiffness to make
· Hardness
· Density
tights due to
its flexibility.
The energy used to manufacture it…read more

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What is Vulcanisation? Polymer with cross-links Plasticizers
·Natural rubber is sticky, deforms easily when warm, ·Plasticizer molecules behave like `molecular lubricants.'
and is brittle when cold. In this state it cannot be ·They push the polymer molecules slightly further apart.
used to make products with a good level of elasticity. ·This weakens the intermolecular forces between them
·Vulcanisation is the process in which rubber is and allows the polymers chains to slide over each other
heated at high temperatures with sulphur. more easily, making the material softer and more flexible.
·The sulphur forms chemical bonds, or cross-links, ·Unplasticized PVC, usually called uPVC, is hard.
which link together the chains of individual polymers. ·Plasticised PVC is soft.
·These cross-links lock the material in a regular Sulphur
shape and make the material tougher and less
flexible, increasing its worth and uses.
Various amounts of crystallinity
·By carefully controlling the amount of Vulcanisation PVC and uPVC
branching, it is possible to make polymers
with various amounts of crystallinity.
·This means it is possible to make a polymer
with the exact properties that are required PVC
for a particular purpose. C3 Molecules
Side Branches
HDPE LDPE ·When polythene molecules made from
No side ethene are exposed to pressure, side
branches branches are given off.
· The polymers will still grow but from
Has side multiple branches and will not line up neatly.
branches ·LDPE in an example of this.
High-Density Polythene (HDPE) Low-Density Polythene (LDPE)
The polymer molecules line up regularly to give a The side branches stop the polymer molecules from
crystalline structure. lining up regularly. Its structure is not crystalline.
This means that: This means that:
·The material has a higher density than LDPE. ·The material has a lower density than HDPE.
·The forces of attraction between polymer molecules ·The forces of attraction between polymer
are strong. molecules are weakened.
·The material is stronger and has a higher melting point ·The material is less strong and has a lower melting
than LDPE. point than HDPE.…read more

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Food Additives E Numbers Carbohydrates and proteins
·Colourings: Replace or add [natural] colours. A food additive that has passed ·Many of the chemicals in living things are natural polymers.
·Flavourings: Gives the food a certain taste safety tests to allow its legal use in ·Animals and plants need natural polymers like proteins and
·Sweeteners: Increase sweetness and replaces the EU is given an E number. carbohydrates.
sugar in products using artificial sweeteners such ·E100 series: Colours ·Food contains natural polymers which are broken down
as aspartame. ·E200 series: Preservatives during digestion into soluble compounds.
·Emulsifiers: Help to mix together substances ·E300 series: Antioxidants ·These are absorbed into the blood and transported around
which do not easily mix, such as oil and water. ·E400+ series: Emulsifiers, stabilisers the body.
·Stabilisers: Stops these substances separating and other additives ·The breakdown products are then used by the body to
again after they have been mixed. make new polymers, during a process called Synthesis.
·Preservatives: Prevents growth of microbes
such as bacteria in foods during storage to Protein
increase shelf life. Amino Acid
·Antioxidants: Prevents reaction of chemicals in Preserving and Polymers
food with oxygen in the air. Processing Food Natural
·Diabetes is a condition where the amount of
Sugar Molecule
glucose in your blood is too high because the
body cannot use it properly.
·Insulin is the hormone produced by the C3 Plants make their own food through
pancreas that allows glucose to enter the body's photosynthesis. They require hydrogen,
cells, where it is used as fuel for energy. carbon, oxygen, NPK and water for growth.
·Glucose comes from digesting carbohydrate
·Intensive farming involves using loads of
and is also produced by the liver. Diabetes Farming artificial fertilisers, herbicides and pesticides
Type 1 and means growing just one crop year after
Type 2 Diabetes year.
·Organic farming aims to produce crops
Adults, or over 40' without using artificial fertilisers.
Children and
s; greater risk of
Who it teenagers; ·High Blood Glucose Level Natural Cycle of Nutrients
those who have
affects adults under Pancreas produces insulin which ·As plants grow they remove NPK from the soil and it
poor diets and/or
the age of 40 enters the blood. Insulin allows becomes less fertile.
are overweight
the glucose to be absorbed by ·Farmers need to be able to replace elements that are
body cells, reducing blood glucose. removed by plants and stop weeds, pests and disease.
The pancreas The body no ·These elements are returned to the soil when living
How it ·Low Blood Glucose Level
stops making longer responds organisms die and decay, or when animals eat other living
works Pancreas stops producing insulin.
enough insulin to its insulin things.
This results in less glucose being
Injections of absorbed by the body cells and ·These processes means that there is a continuous cycling
How it is insulin for life Exercise and more to accumulate in your blood. of elements.…read more


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